Metaproxy XML configuration snippets can be reused by other
filters using the XInclude standard, as seen in
the /etc/config-sru-to-z3950.xml example SRU
configuration.
<filter id="sru" type="sru_z3950">
<database name="Default">
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
href="explain.xml"/>
</database>
</filter>